Paint matching powdercoat to other colors

Please note: Readers are responsible for their own sacrifices to the blood god. Safety first– if you injure yourself implementation of this guide; expect we’ll take no responsibilities. Commentors at Hack-A-Day have indicated that MEK is flammable (as does the label) – so please take the appropriate precautions.

Powdercoat using this method appears to be every bit as robust and scratch resistant as normal powdercoat. The author has seen no negative material properties from using MEK instead of a powder coating gun (electrostatic).

For the beginner; Harbor Freight may be a good stop for the primary colors – they usually carry White, Red, Black, and Yellow. Unsure about Green and blue. I also use HF touch up paint guns, HLVP, and airburshes to apply my MEK solutions. Caswell plating is also a good source for many a color. MEK can be purchase in the paint area of most home improvement stores – I buy mine at Lowes.

I wanted to paint match the powder coat because my chair controls have began to peel and rust. They’ll need to be redone so I wanted them to match the newly retr0brightedside panels.

While the used of the color cue is a good starting place – it isn’t required; you can manually mix colors by eye until you get it right… as you’ll see; I used the color cue to get initial color suggestions (or base colors if you will); then added pure white to bring the color closer to that of the plastics.

I started by measuring the sRGB color of a retr0bright-ed side panel using my Pantone(r) Color Cue(tm) device which I got off of Ebay several months ago and it came up with r246g230b198. I pulled these values into the RGB to commercial Tints page at EasyRGB.com. This gave the closest RAL numbers which to match to. I then went to google and did a search for RAL-1013 powder coat which returned a result to powder365.com for their ” Oyster White ” powder coat. Then using the HTML code #F6E6C6
I also used the RGB browser to convert to “RAL Classic” listed six colors with % equivalent matches to my original scanned color.

During my research; I also came across a post to caswellplating.com’s forums which talked about mixing the powder with MEK to “melt” the powder into liquid form for the purpose of correct a blemish on an existing powder coated part. This sparked an idea – why not use the MEK to mix powders together to get an even better color match. I have a quart of MEK in the garage – so it was time to experiment.

I knew the grey wouldn’t really match – it was too grey; so I used MEK to melt it and used a hobby paint brush to apply it to the scrap piece. I then used regular power coating equipment to lay down the almond and oyster for comparison. For the last color; I decided to mix some grey, 2 TSP of pure white (purchased at Harbor Freight), 2.5 TSP of oyster together with a generous helping of MEK to turn the powder to a grey-white “milky” formulation. I applied this with a paint gun:
From Left to Right: RAL-7035+MEK (under thumb), Almond, RAL 1013, and MEKMix

The Right most Grey is “uncured” IE that is how it goes on being applied with a paint gun. Looks fully cured already. and the lines were created with standard blue painters tape. Be-aware – that MEK powder liquid acts just like any paint… it will dry on everything. so protect from over-spray and wear gloves. Unlike the powder form of powdercoat; it can’t just be wiped off of surfaces.

The cool thing about MEK powder-liquid is reportedly it can be used on Plastics and Wood… using low cure temperatures. Ideal for paint matching on cases or other non-metal projects.

With MEK; it looks like one could color match any color given enough patience and primary colors to choose from. Now with this knowledge; it was time to do some actual paint mixing for the purpose of matching the side panels.

I went to work on the control panels:

As you can see the control panels are in need of some TLC. As typical for this machine; the Fire control panel label has begun to deteriorate and is peeling away from the metal. So I removed the label manually – then used Xytol to soak the piece for about 5minutes to soften the label adhesive so it could be removed with a plastic paint scraper. I continued cleaning/soaking the bracket until all the label residue was removed:

Then I sandblasted the bracket w/ ALO2 to remove the rust and other residue. And then finally; I wiped the bracket clean with some clean MEK to remove and remaining dust and oil from the surface.

I then proceeded to powdercoat the underside to the bracket with the Oyster White Powder coat.
For the front; I did an MEK liquid mix as discussed previously. This time I started with a base of 2.5 TSP of Oyster White powder coat and added 1.5TSP of pure white Powder coat. I then mixed with approx 1/4cup of MEK to form a 2% milk-like consistency. I color checked the mixture by using a small paint brush to apply the color to the underside of on of my plastic pieces. This mixture was nearly a spot on match to the plastic so I decided to go with it. I loaded the MEK liquid powder coat to my touch up paint gun

And painted the front / sides with this MEK paint match. Here it is “air cured”:

Once it is dry to the touch / safe to handle (usually about 20minutes); I place the bracket in my powder coat toaster oven for initial curing. during my test runs; I noticed that if you attempt a full cure (400F / 20minutes) with the MEK solution still wet – it will “Boil” the paint leaving rough spots. So I put the piece in the oven at 150F / Warming setting for 10minutes to allow the MEK to evaporate. Then I crank the piece up to 400F for 20minutes for the final cure.

Once the piece cooled to room tempeature; I did a test match against a retr0brighted piece. First; here’s the stock Oyster White (back of bracket):
Notice the slight yellow hue vs the plastic piece.

Here’s the MEK paint match 1.66:1 (oyster to pure white):
I call that a match!

What do you mean by Gun?
If you mean the sprayer which applies the MEKed (liquid) powder coat; then MEK or Xylol will do a good job of cleaning the sprayer.
On my AirBrush; I use MEK to clean it as it doesn’t take much.

I have been looking and looking for info on mixing powder paint with MEK. I am so glad to have come across your Blog. I realize that you cured your pieces but what I want to do is this. I want to paint cement flooring. I have heard some companys have done this and it turns out great. I will try to mix a little bit at first and then make a forumula to increase the amount. If you have any pointers I would be glad to hear them.

I was told this by one of the Dupont reps. As soon as I have some time I will try to mix up a small batch with power coat that I have and try a small area. It is suppose to be quite durable. Its a good way if it works to use up recycled powder paint.

I just stumbled across this thread whilst searching for powder coat mixing tips. A fantastic blog and I am very grateful for your very detailed description!

I do have one question though. I am looking at powder coating a car water pump and so I need to limit the bake temperature to about 110*C max to avoid damaging the seals etc. I like the idea of using MEK to then spray on the powder coat. You mentioned you can then bake at a lower temp for plastics or wood, do you know / have you experimented with what temp works, and how durable the finish is afterward?

I’m not 100% sure you even need to “Cure it”. MEK basically turns the powdercoat into a “paint”… so you could just leave it that way.

Is the water pump plastic housed or does it just have orings?
If it’s a plastic housing; then it might be an issue spraying MEK onto surface of the plastic. MEK works with the powder because it dissolves the plastic particles into a plastic liquid which can then be mixed. you’d end up doing the same thing to the plastic housing. In the powder/mek solution; it’s probably not enough to worry about; but your mileage may vary.

I haven’t experimented with powdercoating anything other than metals; so can’t really provide any useful data.
I’d say try it and see what’s the final result…. just be prepared to have to buy another pump if things go really south.

On the piece I did on the blog; the coat was very resilent even before bake. I did the bake just to be paranoid. I don’t have any tools to measure abrasion resistance or other properties of the MEK powdercoat; so YMMV.

Finally; if your worried about overall baking; you might try using a heat gun to cure the powdercoat in sections. I haven’t tried this; but I imagine it’s work with enough patience.

Yes it made sense after I tried it, pretty straight forward and using good judgement on the mix. I got it to mix perfect and I got it to spray nicely out the gun but it looked like crap when it came out the oven. It stuck really good to the scrap metal I used but it had a crackled look to it as if it reacted to something. Maybe I am missing a step or maybe I’m using the wrong kind of powder, not sure.

Did you let the MEK/powder mix completely dry before baking it? I’m pretty sure I let my mix “cure” in the texas heat for several days to be sure the mek had evaporated.
I guess the powder type could make a difference.